. >> reporter: today paul ryan admitted to missteps, including the 47% comment. but at the end of the day, we're giving people a very clear choice. >> reporter: ryan was asked the specifics of the tax plan, both romney and ryan have yet to detail their tax cut. now romney is preparing for the debates in boston, massachusetts with senator rob portman standing in as president obama. he is working on sharpening his message. meanwhile obama campaign says that obama is working on shorter, crisper answers. before he gets started, he will speak at this campaign event right here in las vegas. >> kristen welker tonight. >>> we're joined by nbc's chief white house correspondent chuck todd, lay it out for us. how important are the debates in this particular election? >> at this point in time in the campaign, the stakes are enormous for mitt romney. he is behind, you can argue by how much he's behind, is it as bad as it looks in some polls in places like ohio or florida, but the bottom line is he's behind. he needs to come out basically not just even in the presidential, but